The Persian Gulf (PG) is a marginal sea with unique geomorphology and ocean currents, as well as various sub-basins with specific sediment characteristics. In this study, grain size distribution and microscopic examination of coarse-grained particles of 52 surface sediments of the Iranian part of the PG were performed to assess the distribution and physical characteristics of surface sediments and their link to the environmental conditions. Results showed that the seafloor of the middle parts of the PG bottom is covered by silt and sandy silt with a coarsening trend from shallower to deeper waters. At the NW part (submerged Arvand Delta) and the SE part (Strait of Hormoz) of the PG, however, coarser grains of silty sand, and locally, gravelly muddy sand dominate. High-energy density-driven bottom current leaving the PG from channelized deeper areas is likely responsible for removing fine grains, resulting in the accumulation of very poorly to poorly sorted coarse sediments (shell fragments and relict particles) in the deep bottom areas. This hard bottom, in turn, provides a proper surface for some epifaunal communities such as corals and foraminifera. The Iranian offshore basins, on the other hand, are dominated by well to moderately sorted silt to fine sand terrigenous particles. These finer sediments contain a relatively high organic matter with high pellet contents. Altogether, the sedimentation regime of the basin is under the influence of complex hydrodynamic conditions, different bottom materials (relict and bioclasts), the proportion of terrigenous components, complex bottom topography and climate.

波斯湾（PG）是一个边缘海，具有独特的地貌和洋流，以及具有特定沉积特征的各种子盆地。在这项研究中，对 PG 伊朗部分的 52 个表层沉积物的粗粒颗粒进行粒度分布和显微镜检查，以评估表层沉积物的分布和物理特征及其与环境条件的联系。结果表明, PG 底部中部海底被粉砂和砂质粉砂覆盖, 由浅水向深水呈粗化趋势。然而，在 PG 的 NW 部分（淹没的 Arvand Delta）和 SE 部分（霍尔木兹海峡），粉质砂的粗颗粒和局部砾质泥质砂占主导地位。高能量密度驱动的底流从通道化的更深区域离开 PG，这可能是去除细颗粒的原因，导致在深底区域积聚极差到分类差的粗沉积物（贝壳碎片和残余颗粒）。反过来，这种坚硬的底部为珊瑚和有孔虫等一些表层动物群落提供了适当的表面。另一方面，伊朗近海盆地主要由良好到中等分选的淤泥到细砂陆源颗粒为主。这些较细的沉积物含有相对较高的有机物和较高的颗粒含量。总之，盆地的沉积状况受复杂的水动力条件、不同的底部物质（残余和生物碎屑）、陆源成分的比例、复杂的底部地形和气候的影响。